The present invention relates to production line processes, and more particularly to improving lot quality for product lots produced on a production line having a plurality of production steps, where at least some of the production steps utilize a plurality of individual tools.
A production line typically refers to a set of sequential manufacturing operations, where each step in the sequence brings the raw material submitted to the production line closer to the form of the desired manufactured product. The product of a given production line may be the final desired product, or the production line may produce an intermediate material that requires additional manufacturing steps, perhaps by traversing one or more additional production lines, in order to obtain the desired overall final product.
It is not unusual for a given production line to include multiple production steps, and some or all of these production steps may in turn employ multiple individual tools or workstations, where each tool is capable of carrying out the desired fabrication for that production step. In such cases each individual product lot may take very different routes through the production line overall, as each tool in a production step that includes multiple tools represents a branch in the flow of product.
While this kind of multiplicity may enhance overall throughput, it presents particular challenges when product lots begin exhibiting flaws or defects. The time and effort required to troubleshoot the entire production line and identify the particular tools and workstations that are generating the defects represents a substantial loss in valuable production time.